DE 29801567 U1 discloses a hearing aid device which can be worn behind the ear, having an earmold which can be inserted into the auditory canal of a user and a flexible mounting bracket connecting the hearing aid device to the earmold, with which the receiver is arranged in the earmold and the mounting bracket comprises electrical conductors to connect the receiver to the hearing aid device which can be worn behind the ear. The mounting bracket is also connected in a detachable fashion both to the hearing aid device, which can be worn behind the ear, and to the earmold by means of a jack socket and jack plug.
With hearing aid devices, an acoustic tube usually leads from the sound outlet support of the receiver to the sound outlet opening of the hearing aid device. To protect against contamination, the sound outlet opening of a hearing aid device is frequently provided with a cerumen protection facility. If a membrane and in particular a closed, i.e. non-porous membrane is used as a cerumen protection facility, an air vent is required for the enclosed volume between the receiver and the membrane for barometric pressure equalization purposes. This rear ventilation of the closed membrane ensures that the static pressure on both sides of the membrane is equal and corresponds to the ambient air pressure. A hardening of the membrane with the resulting acoustic disadvantages is hereby avoided.
The receiver itself also requires a rear ventilation of the receiver membrane for barometric pressure equalization of the enclosed volume between the receiver membrane rear side and the receiver housing and not connected with the sound outlet opening of the receiver. For this purpose, an opening is provided in the housing of the receiver, typically in the form of a high-precision borehole. A connecting channel can also be present, which connects the volumes on both sides of the receiver membrane with one another. In the simplest case, this connecting channel is generated by at least one small hole in the receiver membrane. The borehole in the receiver housing as well as the holes in the receiver membrane must be small in order to avoid acoustic feedback and to not unnecessarily reduce the level of efficiency of the receiver. They acoustically represent a low pass with a typical cut-off frequency in the range of 1 Hz or an acoustic voltage divider with a strong attenuation.
If a receiver has both a ventilation opening in the receiver housing and also a ventilation channel between the two sides of the receiver membrane, the barometric pressure equalization is in principle thus also possible for cerumen protection between the receiver and an air-tight membrane.
Hearing device receivers and in particular ventilation boreholes of receivers of this type are heavily susceptible to contamination, for which reason the air ventilation is usually routed into the interior part of the hearing aid device, in which a relevant receiver is used. The surrounding hearing aid device housing protects the small borehole from direct contact and/or from a direct connection with the auditory canal, in which the relevant hearing aid device is used. The air exchange with the exterior air which is required for the barometric pressure equalization is then carried out by way of leaks in the hearing aid device housing which are already present, in the region of the battery compartment or operating elements for instance.